Cooling unit for refrigerators



March s, 1935.. R. M. HYDE l 1,993,111 I COOLING UNIT FOR REFRIGERTORS Filed Dec. 15, 1931 2 s1wms-shee' 1 ATTORNE S March 5,1935.

i l um RlvLl-IYDE Y C OOLING UNIT FORA REFRIGERATORS Filednec. 15, '193.1

2 Sheets-Sheet 2 lNvENToR POZZZ?? M. Hyde.

Patented Mar. 5, 1935 UNITED STATES v 1,993,171 COOLING UNIT Foa nnFaIGEaA'roas Rollin M. Hyde, Detroit, Mich., assignor to Mcy Cord Radiator and Manufacturing Company,

Detroit, Mich., a corporation of Maine Application December 15, 1931, Serial No. 501,141

15 claims.

This invention relatos to evaporators or cooling units particularly adapted for use in mechanical refrigeration, an object of the invention being to provide an improved refrigeration unit of 5 the general type employing a pipe coiled or wrapped around a casing or other' support vand in which the pipe preferably is so constructed as to increase the heat exchange capacity of the unit.

A further object is to provide a refrigeration cooling or evaporating unit in which the piping coils surrounding the lcasing are formed of partly round pipe which has a fiat side arranged in close contact with the flat surfaces of the casing so as to provide a more elcient thermal conl tacui; preferably continuously in the length of the A further object of the invention isl t provide a heat exchange unit including coils of tubing adapted to contain a refrigerant fluid, in which the tube coils are arranged to form a housing,

. such as for ice trays, and in which the improved construction materially enhances the heat exchange capacity of the unit while permitting substantial economies V in production.

A further object is to provide a heat exchange unit including a coiled tube particularly adapted to contain a refrigerant fluid and in which the tube is formed in a novel and improved manner to increase its heat absorbing capacity. In accordance with one aspect of the invention this may be accomplished by providing a heat absorbing fin in the length of the tube and preferably forming the same from the metal of the tube.

Other objects of this invention will appear in the following description and appended claims reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a .front elevation, partly in section, illustrating a heat exchange unit embodying one form of the invention` Fig. 2 is a top plan view of the unit illustrated in Fig. 1.

Fig. 3 is a fragmentary sectional view taken substantially on lines 3-3 of Fig. l.

Fig. 4 is an enlarged detail section illustrating a portion of the unit.

Fig. 5 is a fragmentary longitudinal section illustrating another form of the invention.

Fig. 6 is a front elevation ofanother VAembodiment of the invention.

Fig. 'I is a top plan view thereof.

8-8 of Fig. 6.

Figs. 9, 10, 11 and 12 are similar fragmentary sections illustrating further embodiments.

Figs. 13 and 14 are fragmentary sections illustratingalternative methods of uniting the tube coils to the casing.

Fig. 15 is a diagrammatcal view illustrating a method of wrapping the ilat sided tubing about a casing or mandrel, as the case may be.

Before explaining in detail the present invention it is to be understood that @the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Alsoit is to be understood that the phraseology or terminology employed herein is for the pur-l pose of description and not of limitation, and it is not intended tolimit the invention claimed herein beyond the requirements of the prior art.

In the present instance, by way of example, the invention is embodied in a cooling unit or evaporator particularLv designed for mechanical or electric refrigerators adapted for household purposes. illustrated in Figs. 1-5 inclusive, 13 and 14, is preferably provided with a supporting casing or housing 9 of sleevelike character adapted to support the usual ice trays.' 'This casing or sleeve may be formed from a single metal sheet, such as sheet steel, bent into substantially rectangular shape with the meeting edges overlapped and welded together to provide a substantially.rigid support. The front and rear edges of the casing are formed with beaded edges as by curling each edge over aheavy wire insert ll bent into the required shape with the ends buttwelded. The refrigerating fluid is circulated, in the present instance, through a tube or pipe which is wrapped in spiral fashion around the casing or support 9, this tubing preferably being steel seamless tubing and preferably consisting of a single length which is formed in such manner in accordance with the present invention as to provide a uniform contacting surface with relation to the casing and thereby increase the heat exchange capacity `of the unit. p

'I'he coiled tube or pipe, indicated in general at 12, has a portion 13 thereof extending horizontally, across the topof the unit to the front end of the casing, and at the latter end of the casing the tube is wrapped spirally to provide` a succession of contiguous coils. In the present To this end the unit, in the forms 'opposite end 13 of the pipe.

example the coils are formed with parallel courses 14 at the bottom of the casing and angular courses 15 extending across the top of the casing on the bias, and at the end of the section the pipe terminates in -a portion 16 adjacent the As indicated by the arrows in Fig. 2 the refrigerant enters the piping at the end 13, and flows continuously through the several coils and out through the opposite end 16 of the pipe or tube.

As illustrated particularly in Figs. 3 and 4, the tube 12 is attened at one side b to provide a preferably continuous flat surface adapted to conform to the flat surfaces of the casing 9 and producing an intimate contacting relationship between the casing and the coiled tube. 'I'his construction has the distinct advantage of`producing an efficient thermal contact and increasesv the capacity of the unit in effecting a rapid transfer of heat to the refrigerant owing through the coils. Thus the tube 12 is preferably of half round formation having a flat side of relatively large surface area and a crown side 12a. In wrapping the tube about the casing in spiral manner so as to cause certain courses 15 to extend angularly with relation to other courses 14, the bends in the tube at the corners are made in such manner as to cause the at surfaces 12b of the tube coils to hug the casing continuously in the length of the tube.

The unit may be suspended by means of suitn able brackets or hangers 17 from the top wall of a refrigerator cabinet, a portion of which is indicated at 18. The hangers 17 in the present instance are provided with angular portions 17a which are spot welded to the tube 12, and at their upper ends are also provided with angle portions 17b bolted to the cabinet. Within the casing 9 are horizontal strips 19 which serve to support suitable ice trays 20.

In the embodiment illustrated in Fig. 5 the construction is substantially-the same as above described with the exception that the tube 12 is formed, in this instance, with an exterior n 21 which is adapted to increase the heat absorbing capacity of the unit. In forming a tube of thisl constructionone side of the crown may be subjected to pressure by any suitable means, such as by rollers or dies, and a continuous projecting fin 21 thrown up from the crown side in the form of a longitudinal fold of the wall. 'I'he opposite side of the tube has the continuous flat face 12a adapted to provide, as above described, a direct surface contact with the exterior surface of the casing. The refrigerant flows through the series of tubecoils and by virtue of the integral fin 21 as well as the at contacting surfaces 12a the heat exchange capacity of the coils is materially increased, thus producing a most efficient cooling both of the interior of the casing as well as the surrounding atmosphere.

It will thus be seen that asubstantially perfect bearing on the sleeve or casing 9 is provided with a tube coiled or wrapped and formed in accordance with the present invention, thus providing a higher thermal transfer as compared with previous practice where a round tube has been utilized and which only has a point contact with,

the casing. A rapid heat flow is produced not only by means of the flat surfaces 12a but also by means of the projecting fin 21 which preferably extends the full length of the spirals and provides a very substantial surface exposure. The sleeve or casing 9 as well as the tube 12 are preferably formed of steel and may be welded together, if

4construction also enables the entire unit to be porcelain enameled, as shownat 21a in Fig. 4

which cannot be accomplished with previous units where brass or copper material is used and where it has been necessary to solder the round tubes in position.

vWith reference to Figs. 6 to 12 inclusive, it will be seen that the tube coils may be utilized without an interior supporting sleeve.or casing. In these instances the coils provide in themselves the housing for enclosing and supporting the ice trays 20.

'I'he tubing 25 in Figs. 6, 7 and 8 may be ilattened to produce a relatively wide, shallow pas sage 26 increasing the surface contact of the refrigerant. The outer side of the tube may be subjected to pressure, as by rollers or dies, to produce a longitudinal fln 27. In this embodiment the tube housing is made up of superimposed spiral wrappings produced by first winding the tube over a removable mandrel and then rewinding the same tube over the first. series of coils. As illustrated, by way of example, the tube may first be wrapped, starting with the longitudinal pass A, to form the inner series of coils, at the end of which the tube may be looped at B and wrapped in the opposite direction with the outer courses lying snugly between the ilns 27. Instead of the loop B a coupling may be interposed at this point joining two lengths of tubing. The superimposed courses are' preferably secured together by welding or in any other suitable manner.

In Fig. 9 the tubing 12 is 4arranged similarv toFigs. 1 to 3 inclusive, except that in this instance the supporting sleeve or casing is not employed. Thevconstruction and arrangement of -metal strip 29 wrapped spirally around the tube coils as illustrated. 'I'his strip may be provided with a flange 30 forming a continuous spiral iin projecting from the tube courses. The strip 29 is preferably fastened to the tubing by welding and provides not only a support for the tube coils to which the hangers 17 are attached, but also contacts with the tube over the maior portion oi' the outer surface area thereof.

In Fig. 12 the tubing 25 is wrapped in a single series of coils, and the tube coils may be supported and held together by means of a flat metal strip 31 wrapped spirally around the tubing and welded or soldered thereto.

In cases where it is necessary to porcelain enamel the unit it is important that the exposed surfaces of the steel tubing and other parts be clean and free from solder or any welding material used, such as copper, otherwise the enameling job is imperfect. In production it is often diiilcult to prevent the welding or soldering material from flowing ontoth'e exposed surfaces. To overcome this diillculty thetube', such as the half round tube 12 in Fig. 13, may be formed along the dat side thereof with a groove 32 provide inga sufficient space for a copper wire 33. Upon application of heat the melted copper will ilow between the adjacent surfacesof the tubing and support 9, effectively brazing the parts together and maintaining the exposed surfaces'of the tubing clean. Alternatively the casing 9 may be formed with a spiral groove 34 effective to receive the wire 33, which, it will be understood, may be copper or any other suitable material.

In wrapping the tube, such as the half round tube 12, in spiralfashion I have found that in bending the tube on the bias around the corners Vof the casing or mandrel it is necessary to stretch the crown of the tube while holding the flat side from collapsing or buckling inwardly. 'Ihis may be accomplished in the manner illustrated in Fig. 15. The casing 9 (or mandrel) is-supported and revolved in the direction of the arrow. Extending into the tube 12 is a iixed arbor 35 having the required shape nose. As the tubing is fed forwardly and wrapped spirally around Vthe support the arbor holds the at side of the tube from buckling and permits the necessary stretching ofthe metal at the outer surface to produce the angular bends in the tubing.

It will be understood that the modifications illustrated in Figs. 13 and 14 are applicable to and may be embodied not only in the unit shown in Figs. l to inclusive but also in connection with the other forms of the invention, i. e. Figs. 6, 7, 8, 11 and 12. Moreover, where the casing 9 is dispensed with the ice trays 20 may be'supported on strips 19 welded or secured directly to the tubing as shown in Fig. 6.

I claim:

1. A refrigeration unit comprising a support and a pipe wrapped in spiral manner about the support, said pipe having a'continuous flat side in substantially uniform contact with the face of the support to increase thel heat transfer from one to the other, and also having an outer crown side provided with a iin formed in its length.

2. A refrigeration unit comprising a support and a tube wrapped in spiral manner about the support, said tube having a continuous ilat side in substantially uniform contact with the face of the support to increase the heat transfer from one to the other, said tube also having an outer crown side provided with a substantially continuous heat absorbing nn pressed from the metal of the tube.

3. An evaporator unit comprising a support, a lengthof tube wrapped in successive coils and carried by said support, the outer side of the tube having in 'its length a projecting iin formed as a longitudinal fold of the tube wail.

4. An evaporator unit comprising a flat sided tube formed into spirally arranged coils providing a housing for an ice tray or the like, and a spirally coiled metal strip having its surface in thermal contact with said tube and secured thereto.

5. An evaporator unit comprising a flat sided tube formed into spirally arranged coils providing a housing for an ice tray or the like, and a spirally coiled metal thermal contact thereto, and a iin tube.

strip having its surface in with said tube and secured 6. An evaporator unit comprising a support, a ilat sided tube wrapped spirally to provide a series formed from the metal of said of coils, said support and tube coils being superimposed one upon the other and one thereof being provided with a groove to receive a fusible element.

7. An evaporator unit comprising nat sided tubing formed into superimposed inner and outer sets of spirally arranged coils, each course of the inner set having flat surfaces in thermal contact with flat surfaces of two adjacent courses of the outer set.

8. An evaporator unit comprising at sided tubing formed into spirally arranged coils providing a housing for an ice tray or the like, and a spirally coiled metalstrip overlapping the ilat sides of adjacent tube courses and in thermal contact therewith.

9. An' evaporator unit comprising nat sided tubing formed into spirally arranged coils providing a housing for an ice tray or the like, and a spirally coiled metal strip overlapping the flat sides of adjacent tube courses and in thermal contact therewith, said strip having a projecting iin formed from the metal thereof.

10. An evaporator unit comprising flat sided tubing formed into spirally arranged coils providing a housing for an ice tray or the like, and a spirally coiled metal strip overlapping the at sides of adjacent tube courses and in thermal contact therewith, said tubing having a projecting fin interposed between the edges of adjacent strip courses.

11. A refrigerator unit comprising ilat sided tubing wrapped in successive coils to form a substantially rectangular casing having interior substantially at walls formed by said tubing, the outer side of the tubing having in its length a projecting integral fin.

12. An evaporator unit comprising a support, ilat sided tubing wrapped in successive coils and contacting said support, said tubing' and support having a groove formed between adjacent surfaces thereof, and material located in said' groove for bonding the tubing and support together. Y

13. A refrigerator unit comprising a metal casing and metal tubing in heat exchange relation therewith for conducting refrigerant, said tubing and casing having a groove formed between contacting unexposed surfaces thereof, and fusible material located in said groove for bonding tne tubing and casing together.

14. An evaporator unit comprising flat sided tubing formed into superimposed sets of spirally arranged coils in thermal contact Vwith one another and providing a housing for an ice ti'ay or the like, a tube course'of oneset having a projecting nn interposed between adjacent courses of the other set and in thermal contact therewith.

15. An evaporator unit comprising a'support. and a ilat sided tube wrapped spirally to provide a series of coils, said support having a groove formed therein 'to receive a fusible element.

' acum M. HYDE. 

